PDFGym
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Compress PDF
to 400 KB

or drop one here
Compression level
Target size
Choose a PDF file first.

This page shrinks a PDF to 400 KB, which is 409,600 bytes, a comfortable budget for a few scanned pages or a longer text document. The whole job runs in your browser, so nothing uploads anywhere, and every result is reopened and checked before you may download it.

Fitting your file under 400 KB

  1. Drop the PDF in

    Press Choose a PDF or drag the file onto the page. It opens inside this tab on your own device, which is exactly what you want for application paperwork.

  2. Keep the preset target

    This page opens with 400 KB already filled in, so there is nothing to type. If your cap is different, pick a chip such as 200 KB or 500 KB, or type the exact number yourself.

  3. Press Compress

    Four methods race on your own processor: a fresh structural rebuild, image re-encoding, font subsetting, and a full page redraw that only runs when the other three miss the number.

  4. Check the numbers, then save

    The result shows the final size, the saving and the original size beside a preview. Press Download PDF when the pages still read well; the file lands as the original name plus -compressed.

What each method rewrites inside the file is explained in how it works. The main compress page takes any other cap you might meet.

The application pack that must fit one upload box

Tomas is applying for a junior analyst role, and the hiring portal takes a single PDF capped at 400 KB: CV, cover letter and two certificates in one file. His export, application-tomas.pdf, holds 5 pages at 2.6 MB, mostly because the certificate scans are phone photos at full resolution.

He drops it here, keeps the 400 KB preset and presses Compress. Image re-encoding wins, the file lands at 370 KB, and the preview confirms the certificate seals still read. One upload, first try, before his lunch break ends.

Four to eight pages is the sweet spot for this number: each page gets 50 to 100 KB, enough for printed text, a signature and a stamp. Past ten pages the budget thins, and splitting into two uploads serves you better than squeezing harder.

Spending 400 KB wisely

Colour is the quiet budget eater. A colour scan of black and white paper costs roughly triple a greyscale scan before compression starts, because the scanner defaults to colour whether the page needs it or not. If you still hold the paper originals, rescan text pages in greyscale; if not, this page performs the equivalent step after the fact.

Leave a margin under caps that read "under 500 KB". This tool counts a kilobyte as 1,024 bytes, while some portals count flat thousands, which makes their cap about 2.3% stricter. A file aimed at 400 KB clears either reading of a 500 KB limit without argument, which is why 400 KB makes such a good deliberate target rather than an accidental one.

Neighbours on the same engine: 300 KB when a box is stricter, 500 KB when you may spend more. Size breakdown shows which pages eat the budget before you run.

Why a 400 KB run can miss

A result above the number usually means too many pages for the budget, not a broken tool. Twenty scanned pages at 400 KB gives each page 20 KB, which softens small type. Split the file into parts that each fit, or delete pages the recipient never asked for, then run again.

A second classic is the double squeeze: compressing an already compressed file re-encodes the images again and the softness compounds. Always start from the master export. And a file that asks for a password on open resists the rebuild tricks, so pass it through Unlock PDF first.

When 400 KB is not the right answer

If the form accepts several uploads, one file per document at generous sizes beats one starved bundle: split first, then give each part room to breathe. If the pages only need to be pictures for a chat thread, PDF to JPG pulls them out as images. And if the recipient can take email instead of the portal, a roomy 1 MB file sidesteps the whole fight.

400 KB questions, answered briefly

How many bytes is 400 KB here?
409,600 bytes, at 1,024 bytes per kilobyte. A portal counting flat thousands caps at 400,000, so if a box already bounced your file once, rerun at 390 KB.
How many scanned pages fit in 400 KB?
Four to eight pages stay comfortable, with printed text, signatures and stamps legible. Single page certificates have room to spare; past ten pages, split the file.
Does the text stay selectable at 400 KB?
Yes. Every candidate is reopened and its characters counted against the original, and anything below 98% retention is refused before download.
Is my application paperwork uploaded anywhere?
No. The file is read into tab memory, processed there and written to your downloads. Nothing leaves the machine and no account exists to sign into.
What if the result lands at 405 KB against a 400 KB box?
Lower the target a touch, to 380 or 390 KB, and run once more from the master. Or drop one unneeded page, which often saves more than any setting.

Keep shaping the file after the squeeze

Split, inspect, convert or protect around this run. Every tool below runs in the tab with no account, and rechecks its output first.